1. Technical Field
The present invention relates to a control apparatus for a motor-generator, the apparatus being used by changing the operation mode thereof between an electric power generation mode as a generator and a mechanical power generation mode as a motor.
2. Related Art
As a simple speed-increasing method for a brushless motor, a driving method using a circuit disclosed in, for example, JP-A-2008-306914 is known. This example requires a sinusoidal PWM controlled inverter to obtain stable rotational speed extensively. Hence, an expensive magnetic pole position sensor is required. In addition, since all elements are required to be subject to switching, switching losses increase, thereby lowering the system efficiency, a large cooling unit is required for the inverter, and protection against switching noise is required. Accordingly, although the driving method can be used for an expensive apparatus, the driving method is not suited to be used for, in particular, electric components for a light automobile and a motorcycle from a cost viewpoint.